code-hygiene

Code Hygiene

Don't leave -- or write -- code that lies, hides, or that git (or an existing solution) already owns. Every line is a permanent liability someone must read, test, and carry forward, so each must earn its place. This skill is language-agnostic and guides both authors and reviewers. This skill only deletes; its constructive siblings shape what survives -- code-structure (the units and their contracts) and readable-code (how a body reads). Comment truthfulness is comment-hygiene's. (Python-specific pitfalls live in pythonica:python-anti-patterns; documentation prose in docs-patterns.)

Dead code & speculative generality

Code no live path needs is dead -- delete it; don't add what isn't needed yet.

Dead / commented-out code

Rule: Delete dead, unreachable, and commented-out code. Git holds the history -- recover it with git log -G if ever needed. Never comment code out to keep it "for later"; version control is the "for later."

Test: unreachable (after return / throw / break), unused (no live caller, import, or reference), or disabled/commented "just in case" -> delete.

Orphaned abstractions / speculative generality

Rule: Don't build for a future that hasn't arrived (YAGNI). A helper, wrapper, config knob, interface, or parameter with no live consumer is dead weight -- remove it, or don't add it.

Test: zero live callers, or added only for a hypothetical future need? -> delete / don't write. Generalize when the second real use appears, not before.

Debug / scaffolding output left behind

Rule: Strip ad-hoc debug and instrumentation output -- print, console.log, debugger, breakpoint(), dbg!, var_dump -- before merge. It was scaffolding to inspect state during development, not shipped behavior.

Test: is this line an ad-hoc trace a developer added to watch state, rather than an intentional logger call? Yes -> delete.

Contrast: a real logger call (logger.*) is the sanctioned channel for output that should ship -- see logging-patterns.